Make image.Color.RGBA return 16 bit color instead of 32 bit color.

R=rsc
CC=golang-dev
http://codereview.appspot.com/1388041

2 files changed, 11 insertions, 11 deletions

diff --git a/src/pkg/image/png/reader_test.go b/src/pkg/image/png/reader_test.go
index 68aab7832..1dc45992e 100644
--- a/src/pkg/image/png/reader_test.go
+++ b/src/pkg/image/png/reader_test.go
@@ -76,9 +76,9 @@ func sng(w io.WriteCloser, filename string, png image.Image) {
 		io.WriteString(w, "PLTE {\n")
 		for i := 0; i < len(cpm); i++ {
 			r, g, b, _ := cpm[i].RGBA()
-			r >>= 24
-			g >>= 24
-			b >>= 24
+			r >>= 8
+			g >>= 8
+			b >>= 8
 			fmt.Fprintf(w, "    (%3d,%3d,%3d)     # rgb = (0x%02x,0x%02x,0x%02x)\n", r, g, b, r, g, b)
 		}
 		io.WriteString(w, "}\n")
diff --git a/src/pkg/image/png/writer.go b/src/pkg/image/png/writer.go
index 06b6dcdc3..e186ca819 100644
--- a/src/pkg/image/png/writer.go
+++ b/src/pkg/image/png/writer.go
@@ -37,7 +37,7 @@ func opaque(m image.Image) bool {
 	for y := 0; y < m.Height(); y++ {
 		for x := 0; x < m.Width(); x++ {
 			_, _, _, a := m.At(x, y).RGBA()
-			if a != 0xffffffff {
+			if a != 0xffff {
 				return false
 			}
 		}
@@ -101,13 +101,13 @@ func (e *encoder) writePLTE(p image.PalettedColorModel) {
 	}
 	for i := 0; i < len(p); i++ {
 		r, g, b, a := p[i].RGBA()
-		if a != 0xffffffff {
+		if a != 0xffff {
 			e.err = UnsupportedError("non-opaque palette color")
 			return
 		}
-		e.tmp[3*i+0] = uint8(r >> 24)
-		e.tmp[3*i+1] = uint8(g >> 24)
-		e.tmp[3*i+2] = uint8(b >> 24)
+		e.tmp[3*i+0] = uint8(r >> 8)
+		e.tmp[3*i+1] = uint8(g >> 8)
+		e.tmp[3*i+2] = uint8(b >> 8)
 	}
 	e.writeChunk(e.tmp[0:3*len(p)], "PLTE")
 }
@@ -261,9 +261,9 @@ func writeImage(w io.Writer, m image.Image, ct uint8) os.Error {
 			for x := 0; x < m.Width(); x++ {
 				// We have previously verified that the alpha value is fully opaque.
 				r, g, b, _ := m.At(x, y).RGBA()
-				cr[0][3*x+1] = uint8(r >> 24)
-				cr[0][3*x+2] = uint8(g >> 24)
-				cr[0][3*x+3] = uint8(b >> 24)
+				cr[0][3*x+1] = uint8(r >> 8)
+				cr[0][3*x+2] = uint8(g >> 8)
+				cr[0][3*x+3] = uint8(b >> 8)
 			}
 		case ctPaletted:
 			for x := 0; x < m.Width(); x++ {